Mechanical operation of smelting furnaces



3 Sheets-Sheet 1 8 O mm 01M m Wm M m M w w Feb. 16, 1937. H, R. M MICHAEL MECHANICAL OPERATION OF SMELTING FURNACES Filed July 26, 192a,

elf/to Feb. 16, 1937. H. R. MacMlCHAEL 2,070,910

MECHANICAL OPERATION OF SMELTING FURNACES Filed July 26, 1923 5 Sheets-Sheet 2 avwe nkoz HUGH R.. MACMICHAEL Feb. 16,- 1937. H. R. M MICHAEL MECHANICAL OPERATION OF S MELTING FURNACES Filed July 26, 1928 5 Sheets-Sheet 5 awvenboz HUGH R. MACMICHAEL FIG Patented Feb. 16, 1937 UNITED STATES PATENT OFFICE MECHANICAL OPERATION OF SMELTING FURNACES Hugh R. MacMichael, El Paso, Tex, assignor to American Smelting and Refining 00., New York, N. Y., a corporation of New Jersey Application July 26, 1928, Serial No. 295,419

9 Claims.

may take, a Scotch hearth such as used in lead smelting is provided with a carriage which is arranged to move step-by-step therealong and have mounted thereon various operating mechanisms, such as a mechanical poker and a mechanical shovel, to rabble and spread respectively the material in the hearth.

Suitable devices are provided to automatically stop and start the carriage and operating mechanism at the ends of the hearth and the stepby-step mechanism is arranged so that the carriage has substantially no movement while the shovel and poker are operating upon the hearth.

A particular mechanical shovel which may be employed is disclosed in application Serial No. 196,304, filed June 3, 1927, and a particular mechanical poker mechanism which may be employed is disclosed in application Serial No. 200,- 523, filed June 22, 1927.

The invention also consists in certain new and original features of construction and combinations of parts hereinafter set forth and claimed.

Although the novel features which are believed to be characteristic of this invention will be particularly pointed out in the claims appended hereto, the invention itself, as to its objects and advantages, the mode of its operation and the manner of its organization may be better understood by referring to the following description taken in connection with the accompanying drawings forming a part thereof, in which Fig. 1 is a side elevation of the carriage and a section through the hearth;

Fig. 2 is an elevation of the carriage looking toward the back of the hearth;

Fig. 3 is a top plan view of the carriage illustrating the control mechanism;

Figs. 4 and 5 are further details illustrating the control mechanism; and

Fig. 6 is a detail illustrating one of the clutches.

In the following description and in the claims parts will be identified by specific names for convenience, but they are intended to be as generic in their application to similar parts as the art will permit.

Like reference characters denote like parts in the several figures of the drawings.

In the drawings accompanying and. forming part of this specification, a practical commercial embodiment of the invention is shown, but

as such illustration is primarily for purposes of disclosure, it will be understood that the structure may be modified in various respects without departure from the broad spirit and scope of the invention as hereinafter defined and claimed.

Referring now to the drawings, and more particularly to Fig. 1, so much of a Scotch lead smelting hearth as is necessary to an understanding of this invention will be described. The Scotch hearth may comprise the usual basin or trough l, the trough being comparatively narrow and relatively long, as is well understood. At the front edge of the trough, an apron 2 is provided extending the length of the trough, the apron sloping forward and slightly downwardly. At the back side of the trough and extending the length thereof is a back made up of a block 3 having a suitable water space 4 therein for cooling, underneath which are suitable tuyeres 5 for supplying draft to the furnace, as is well understood in the art. A hood denoted generally by I2 is provided, its lower end being disposed close to the hearth efficiently to catch the fume and gases, This construction is well known and no further description is deemed necesary.

Disposed in front of the hearth overhead is a pair of rails II on which the carriage runs. The carriage comprises a suitable framework in which is journalled a pair of axles 6 and 1 which have mounted thereon wheels 8 running on the rails II. The carriage carries the mechanical poker 9 and the mechanical shovel [0, which will be described in detail hereinafter.

The carriage is driven and motion is imparted to the shovel l0 and poker 9 by an electric motor l5. This motor drives a counter shaft l6 suitably journalled in the frame of the carriage and carrying a fly-wheel IT. This shaft also carries a spur gear l8, meshing a pinion IS on the motor shaft, and also carries a pinion driving a large spur gear 2| loosely mounted on the operating shaft 22. Mounted on a sleeve, which is secured to the spur gear 2|, is a sprocket 23 supporting a chain 24 which is also supported on an upper sprocket 25 mounted on an upper shaft.

The operating shaft 22 is suitably journalled in the frame and carries in overhanging relation a. cam wheel 28 inwhich is journalled a suitable buckle or clamp 29 for carrying the poker 9. Secured to the operating shaft 22 is a sheave of an eccentric, the strap 30 of which is connected to a rod 3| pivoted to lever 32 by pivot 33.

Secured to the spur gear 2| is one element 34 of a clutch 21 having suitable teeth, the other element 35 of the clutch having teeth meshing therewith. The second clutch element 35 is feather keyed by key 36 to the operating shaft 22, being free to move longitudinally thereon, but constrained to rotate therewith. A suitable abutment 3? is on the operating shaft between which and the clutch element 35 springs 33 are provided to continually urge the teeth of the clutch elements into meshing relation.

To operate the clutch, the clutch element 35 is provided with a cam surface 39. A suitable lever 40 is pivoted by pivot 4I to the frame and is slidably mounted between guides 42. The lever is provided with a cam follower l3 cooperating with the cam surface 39. The lever 30 is connected to a vertical rod M extending upwardly to a lever 45, pivoted to the frame by pivot 36. The other end of the lever 45 supports a weight 41.

Secured to one axle 6 of the carriage is a ratchet wheel 48. Straddling the ratchet wheel and loosely mounted on the axle is a pawl holder 39 to which is suitably pivoted the pawl 50. The pawl is adapted to engage a shield 52 mounted on the end of a bell-crank lever 53, which is also loosely mounted on the axle 6. The lever 53, is connected by rod 55 to a lever 54 which is fixedly mounted on the shaft 45. The pawl holder 59 has secured thereto an arm 56 which is connected to a link 51 which in turn is connected to a small connector 58 connected to the lever 32 to allow universal motion. The adjustment lever 32 is provided with a plurality of holes to which the eccentric rod 3I may be selectively connected to change the throw of the pawl 55 and hence the distance the carriage is moved with each revolution of the eccentric.

The upper shaft I00 is suitably journalled in the carriage frame and carries a clutch element IllI of clutch III loosely mounted thereon to which is secured the upper sprocket 25. The other clutch element I02 is feather-keyed to the shaft and is normally held in disengaged position by the spring I03. The shaft I00 is geared to the axle I by bevel gears I04 and I05.

To control the mechanism for driving the carriage, so that it may advance step-by-step on its operating trip or pass and return by continuous movement on its return trip, suitable control linkage is provided.

Disposed along the tracks II is a control rail I06 having its ends I01 turned away from the carriage. Suitably pivoted by pivot I08 to the carriage is a control lever I09 having a roller III] at its outer end. The control lever IE9 is also pivoted to the clutch collar of clutch element I32 by pivot II I. A short lever H2 is pivoted to the frame by pivot H3, and a long lever Il is pivoted to the frame by pivot H5. The short lever is connected to pivot I I I and to the long lever by pivot II6.

Disposed along the tracks II at the end of the operating pass or trip is a long stationary rod I IS on which is slidably mounted a contact member H9 and fixedly mounted a stop I20. A long coil spring IZI is disposed between the contact member and stop. The rod H8 is provided with a second stop I22 for limiting the expansion of the spring.

Referring now. to the poker 9, a fulcrum support I23 is provided on the frame for supporting the poker at a point near the edge of the trough I. Pivotally connected to the buckle 29 is a grooved roller I24.

Referring now to the mechanical shovel, the framework of the carriage is provided with a pair of lugs or ears to which the impeller arm 60 is pivotally connected by pivot 6| and a second pair of spaced ears to which a composite lever 62 (Fig. 2) is pivoted by pivot 83. The framework has a bracket member 64 having aligned openings in which is slidably mounted a follower rod 55 having at its lower end a roller 66 engaging the cam surface I25 on the cam wheel 28.

The follower rod is provided with a suitable abutment 68 between which and the plate 59 is disposed a coil spring it, this coil spring acting to continuously urge the follower rod. against the cam surface. The plate 33 is secured in fixed relation to the bracket member by a pair of rods II disposed on either side of the follower rod.

As shown, the impeller arm 39 is curved at its upper end and generally straight for the rest of its length and has secured to one side thereof a pair of spaced lugs I2. A pair of spaced ways or guides '13 is secured to the lugs, these ways or guides being curved, as shown in l, to aid giving the desired peculiar motion to the shovel blade 14. The grooved roller I2 1 on the buckle is disposed between these ways.

Pivoted at the lower end of the impeller arm is a shovel arm ll, this arm comprising a body member having an opening in its middle portion, forming branches (Fig. 2) between which the lower end of the impeller arm is disposed. A

suitable pivot bolt l8 threads the branches and the impeller arm. The front end of the body is suitably forked, and between the prongs of the fork the lower end of the elevating link 19 is suitably pivoted by a pivot bolt 89. The rear end of the shovel arm is provided with the blade M of the shovel which extends longitudinally of the furnace a substantial extent and has a slightly back-curved lower end 85,. as shown in Fig. 1.

The upper end of the elevating link "5% has a suitable loose or universal connection I23 with the composite lever 52 to allow the swinging movement of the elevating link back and forth and the up-and-down movement imparted thereto by the composite lever. rod 35 has a pivot 83 which works in a slot in the composite lever I52 so that the reciprocating movement of the follower may be imparted to the composite lever.

The carriage is shown in Fig. 3 almost at the end of its operating trip or pass. The clutch H1 is normally held disengaged by the spring I83 and the control lever IE9 rides idly along the control rail. The clutch 2's is engaged and the shovel III and poker 9 are being continuously operated; also the ratchet 5D is being reciprocated to move the carriage step-by-step. The parts are so related, however, that all movement of the cariage takes place when the poker and shovel are out of the charge in the hearth, so that, while the poker and shovel operate on the charge in the hearth the carriage is stationary.

As the carriage approaches the end of its operating pass or trip, the long lever II l engages the contact member H9 and compresses the spring I2I as shown in Fig. 3. As soon as the control lever I35 rides off the end of the rail I38, the clutch II! is engaged, since the spring IZI through the linkage IIZ, Il -i exerts enough force to overcome the clutch spring I93. At the same time the clutch II! is engaged, the levers 45, 54 and rods I4, 55 are moved (1) to place the shield 52 under the pawl 59, so that the pawl oscillates idly and (2) to move the lug 33 in the path of the cam surface 39, so that the clutch 2'! dis The follower the cam face 39. engage and the carriage to advance once more engages itself. The cam 39 and the pressure of springs 38 are so arranged that, when the clutch rail, and the clutch spring I53 automatically disengages the clutch, and, operating upon levers 45, E i and links Ml, 55, removes the shield 52 from beneath the pawl 59 and the lug 43 from This allows the clutch 21 to with a step-by-step movement. It will be noted the mechanical connection between the poker and shovel and step-by-step mechanism is continuous and permanent so that there is always a constant relation between the poker and shovel and the position of the ratchet, thus insuring that the carriage is always stationary while the poker and shovel are in the hearth.

The end of the poker 9 will describe a closed path and the charge will be broken up and leveled down and parts of the charge thrown on the apron, all as is described in the above copending applications. The top of the charge, when thus leveled down, under some conditions is illustrated by line 86 in Fig. 1.

The mechanism will cause the shovel to exe cute a movement illustrated by the dotted line and arrows indicated by 3'! in Fig. 1 This shovel will scrape the apron, as shown, and push the charge back, forming the bank which, under some conditions may be illustrated by the line 88 in Fig. 1. The shovel will travel slowly at the front of the hearth but will receive a sudden flip about halfway across the basin which flips the material up against the back of the hearth and causes it to roll forward by gravity, providing a selective action, explained in the above copending applications.

When the poker engages the charge, it breaks up the charge and levels it down and throws part of it on the apron, similar to the old manual operation. The shovel following pushes the charge back, flipping part of it against the furnace back and causing part of it to roll forward with a selective action. The larger particles roll forward the furthest and particles of slag roll down on the apron, from which they can easily be removed. A feeder (not shown) may follow the shovel to feed the charge (which, in the case of lead ores, may be pre-mixed fuel, ore and fume) in such manner as to get the proper distribution across the width of the hearth, or the charge may be fed by hand by workmen as in the old and well-known manner.

By means of the carriage with its above de scribed operating mechanisms and its automatic control features, a Scotch hearth type of furnace or other furnace may be operated substantially automatically to a large degree. The automatic mechanism furthermore insures the proper starting and stopping of the poker and shovel and proper operation of the carriage. By the use of the present invention the operation of a Scotch hearth may be made substantially uniform and when adjustment has been made to obtain the best operating conditions, the device insures continuance of these conditions.

While certain novel features of the invention have been shown and described and are pointed out in the annexed claims, it will be understood that various omissions, substitutions and changes in the forms and details of the device illustrated and in its operation may be made by those skilled in the art without departing from the spirit of the invention.

What is claimed is:

1. In apparatus of the class described, a furnace, a trackway along said furnace, a carriage on said trackway adapted to make operating trips and return trips, a first means on said carriage to drive it on its operating trip, a means on said carriage to drive it on its return trip, interlocking devices for selectively causing said means to drive said carriage, biased means normally causing one means to drive said carriage and holding the other means inoperative, means operable at the end of one of said trips of said carriage for interchanging said driving means, and means along said trackway for holding said driving means in interchanged condition till the carriage reaches the end of its other trip.

2. In metallurgical apparatus, a lead smelting hearth having a relatively long and narrow trough, a carriage adapted to move back and forth along said hearth, a poker and shovel on said carriage for operating said hearth, driving means for imparting a step-by-step movement to said carriage on its operating trip and for operating said poker and shovel only when said carriage is substantially stationary, driving means for imparting a continuous movement to said carriage on its return trip with said poker and shovel clear of said hearth, and devices operable at the ends of said trips for automatically exchanging said driving means.

3. In combination with a furnace, a support, a drive shaft on said support, a cam wheel secured to said shaft, a holder pivoted to said wheel, a poker in said holder, a fulcrum for said poker near said furnace, an impeller arm pivotally connected to said support, a transverse lever pivoted to said support, an elevating link pivoted to said lever, a shovel arm pivoted to said impeller arm and elevating link, a follower riding on said cam wheel and pivoted to said lever, a guide for said follower, a guideway secured to said impeller arm, and a guide member cooperating with said guideway and secured to said holder.

4. In combination with a furnace, a support, a drive shaft on said support, a cam wheel secured to said shaft, a holder pivoted to said wheel, a poker in said holder, a fulcrum for said poker near said furnace, an impeller arm pivotally connected to said support, a transverse lever pivoted to said support, an elevating link pivoted to said lever, a shovel arm pivoted to said impeller arm and elevating link, a follower riding on said cam Wheel and pivoted to said lever, a guide for said follower, spaced ways secured to said impeller arm, and a guide wheel between said ways and secured to said holder.

5. In combination with a smelting hearth having a relatively long and narrow basin, a trackway along said basin, a carriage on said trackway, means for imparting a step-by-step motion to said carriage, a poker on said carriage to poke into the charge, a shovel on said carriage for pushing back part of the charge, and means for causing said shovel and poker to operate simultaneously on different parts of the charge only while the carriage is substantially stationary.

6. In apparatus of the class described, a furnace, a trackway along said furnace, a carriage on said trackway, a drive motor on said carriage, drive wheels on said carriage, a first clutch between said drive motor and drive wheels, an operating shaft, a crank on said shaft, operating devices connected to said shaft for operating said furnace, a second clutch between said motor and operating shaft, drive connections between said operating shaft and said wheels, means for normally holding said first clutch disengaged and said second clutch engaged, a control rail along said trackway, a control member secured to said carriage and adapted to ride on said rail to hold said first clutch in engagement on the return trip of said carriage, linkage connecting said control member and clutches, devices at the end of the trackway whereby, at the end of the operating trip, said linkage causes the first clutch to engage as soon as the control member runs off the rail and opens said second clutch.

7. In apparatus of the class described, a furnace, a trackway along said furnace, a carriage on said trackway, a drive motor on said carriage, drive wheels on said carriage, a ratchet wheel connected to one of said drive wheels, a clutch connected to another of said drive wheels, an operating shaft, operating devices connected to said shaft for operating upon said furnace, a pawl operating on said ratchet wheel, connections directly from said operating shaft to reciprocate said pawl to drive said carriage step-by-step on its operating trip, drive connections from said motor to said clutch, a second clutch on said operating shaft for controlling said operating shaft and driven by said motor, said first clutch having a spring holding it normally disengaged, a control rail along said trackway, a control lever pivoted to said carriage and tosaid first clutch and adapted to trail on said rail to hold said first clutch in engagement to drive said carriage continuously on its return trip, a shield, linkage connected to said lever, to said shield and to said second clutch, devices at the end of the trackway whereby, at the end of the operating trip, said linkage causes the first clutch to engage as soon as the control lever runs off the rail, places said shield under said pawl and opens said second clutch.

8. In apparatus of the class described, a furnace, a trackway along said furnace, a carriage on said trackway, a drive motor on said carriage, drive wheels on said carriage, a ratchet wheel connected to one of said drive wheels, a clutch connected to another of said drive wheels, an operating shaft, a crank on said shaft, a poker and shovel for rabbling and spreading the charge respectively, connections between said crank and poker and shovel, a pawl operating on said ratchet wheel, connections directly from said operating shaft to reciprocate said pawl to drive said carriage step-by-step on its operating trip, drive connections from said motor to said clutch, a second clutch on said operating shaft for controlling said operating shaft and driven by said motor, said first clutch having a spring holding it normally disengaged, a control rail along said trackway, a control lever pivoted to said carriage and to said first clutch and adapted to trail on said rail to hold said first clutch in engagement to drive said carriage continuously on its return trip, a shield, linkage connected to said lever, to said shield and to said second clutch, a slide at the end of the trackway, a contact member and a control spring on said slide, whereby, at the end of the operating trip, said linkage engages said contact member to compress said control spring to cause the first clutch to engage as soon as the control lever runs off the rail and to place said shield under said pawl and open said second clutch.

9. In combination with a smelting hearth having a relatively long and narrow basin, a carriage, means for moving said carriage along said basin,

a poker on said carriage to poke into the charge,

a shovel on said carriage for pushing back part of the charge, means for causing said shovel and poker to operate on the charge, and means for causing said shovel and poker to partake of no substantial movement along said basin whilie operating on said charge.

HUGH R. MACMICHAEL. 

